328 The Natural System of Botany. 



order are so marked, that little more than a single glance ' 

 required to distinguish its members. The flowers are in'he \* 

 forming what is usually called a composite flower. Take th*' 

 Dandelion or the Sun-flower for an example. The involu * 

 is formed of a set of bracts or scales ; and each separate 

 flower has often a bract of its own. The calyx is a papn 

 consisting of bristles or hairs. The corolla is superior, and 

 ligulate or tubular. The stamens are five, and the anthers a" 

 united into a tube. The style is tworcleft ; the fruit an ache! 

 nium, one-seeded, crowned with the pappus. There are three 

 sub-orders in this immense family. Tubuliflor,e, contains 

 all those whose corollas are tubular, regular, and four or fi Ve . 

 lobed. The flowers of these are arranged either in a discoil 

 head, without rays ; as in Lappa (the Burdock), Cnicus (the 

 Thistle), &c, in which the flowers are all tubular and perfect- 

 or in a disk with rays, the disk flowers being tubular and per- 

 fect, while those of the ray are ligulate and imperfect, that is 

 lacking stamens, or both stamens and pistils, as in the Sun- 

 flower and Aster. The second sub-order is Labiatiflor^e 

 in which the corolla of the disk flowers is bilabiate. These 

 are tropical species. The third sub-order is Liguliflor^ : 

 in which the corolla, in both disk and ray flowers, is ligulate 

 (flat or strap-shaped), as in the Dandelion, the Lettuce, &c. 



0r<Zer-— LobeliacEjE. The Lobelia Tribe. 



The plants of this order are readily known by their irregu- 

 larly five-lobed corollas, their coherent stamens, fringed siig- 

 mas, and capsular fruit. They are generally herbs, and their 

 juice is acrid and narcotic. The species of Lobelia, one of 

 which is used medicinally, are the Northern representatives of 

 the Order. 



Order— Campanula ceje. The Bell-Flower Tribe. 



The ornamental Campanulas are much cultivated. None 

 of the order possess any useful qualities. The regular, cam- 

 panulate corolla, five distinct stamens, and hairy styles are 

 characteristics. 



